Optical data transfer systems have an inherent transfer rate capability in excess of 100 gigabits per second. Electronic data transfer systems, on the other hand, are limited to transfer rates of roughly 1 gigabit per second, due to component switching times. Combinations of the above two systems into an electro-optic data transfer system, such as optical communication links, computer data links, etc., are presently limited by the slower electronic transfer rates.
One approach to obtaining a high-performance electro-optic data transfer system is to utilize parallel-to-serial multiplexing and serial-to-parallel demultiplexing of the data, wherein the slower electronic data transfer systems run in parallel, and the higher speed optical data transfer systems comprise fast serial data channels between the multiplexers and demultiplexers. Such a system has a natural applicability to most data transfer tasks in which an N bit binary word is generated. Each such word can be sent via N parallel electronic data transfer systems, each operating on one of the N bits. In this case, the serial optical data transfer system would run at a rate N times that of the individual electronic systems.
Prior systems for performing optical multiplexing and demultiplexing operations have possessed a number of limitations. One limitation is that prior arrangements have not been adapted for implementation using integrated optics technology. A second limitation of prior systems is that they have implemented the multiplexing or demultiplexing operations using blocking optical switches. A blocking optical switch is a switch that either transmits or blocks an optical input pulse. The use of blocking optical switches requires the attendant use of power dividers, and therefore requires higher power levels than optimum. Finally, a limitation of prior systems has been that such systems have been implemented using a tree or branching architecture in which, for example, an optical input signal is switched between one of two paths, and each of such paths is then input into another switch which again divides or switches the pulse between one of two output paths, etc. The coordination of the switching signals in such systems can be a challenging and difficult task.